I have a Kahr PM9. It's having some failures to feed where the slide locks back as if the magazine is empty but the round is nose down. It's as if the bullet it hitting the slide lever. This is a known issue with the PM9 and a lot of people file them down to correct it.

The question is, how should I go about this? I don't want to remove too much. Also, what kind of file should use?

It does sound like the same issue I had with my P380. I found the same sort of info you mentioned: filing the little tab that catches the mag follower. I did mine in 2 stages so that I wouldn't over-do it. The 1st time, I filed about .008" off. This seemed to help at 1st, but the same thing ended up happening a few more times, so I filed off about the same amount again, for a total of ~.015-.016".

You could probably use a jeweler's file or similar, but I already had 4" & 6" smooth files. Either one would work. The nail file isn't a bad idea, but it might not work very long on a relatively tough part like the slide stop lever. If there's a discount tool store around, you should be able to find something for just a few bucks.

Just be careful - go slow & try to keep the same angle on the little tab. You may not need to take off as much as I did, so maybe test it after .005" or so. Like they always say, it's a LOT harder to put a little bit back on.

So, while filling up my new range bag today I deiced to do some investigating and check to see how close the round is coming to the slide lever. I deiced to stick three rounds into the magazine and first check with the rounds pushed all the way back in the magazine. Then check after chambering a round. I did this because I noticed that after chambering a round the next round was pulled sightly forward in the magazine.

First I checked with my carry rounds, Hornady Critical Defense 115gr. With the round all the way back it has no chance of hitting the lever. After one being chambered it's decently close but I don't think there's a possibility of it hitting the lever. I wasn't too worried in the first place considering the shape of the round.

Next I checked with the ammunition I used to break it in that this has been happening with, Remmington UMC Target 115gr. All the way back it's already pretty close. After chambering the first round it's really close. I can see any small variance causing it to trip the lever. I honestly think this has been the problem all along.

Lastly I checked with some ammunition that I was planning on trying to see if I could rule out ammunition as a problem, Federal Champion 115gr. It was even worse. It was only slightly further from the lever on the first round. After chambering the first round the second round was clearly hitting the lever.

After doing some more research it seems that this gun was designed around 124gr rounds. So, I'm going to pick up some 124gr rounds to test with as well. I have to go to the store today and I'm going to find me a small file and get to work.